Various cancer cells or tissues express oligosaccharide sequences which are different from the non-malignant glycosylation of the same cell or tissue type. Examples of the known or speculated cancer associated oligosaccharide structures include: glycolipid structures such as globo-H (Fucα2Galβ3GalNAcβ3Galα4LacβCer), ganliosides: GM1 Galβ3GalNAcβ4(NeuNAcα3)LacβCer, or GD2 GalNAcβ4(NeuNAcα8NeuNAcα3)LacβCer; Lewis-type fucosylated structures such as Lewis a and x Galβ3/4(Fucα4/3)GlcNAc, Lewis y Fucα2Galβ4(Fucα3)GlcNAc, sialyl-Lewis x NeuNAcα3Galβ4(Fucα3)GlcNAc, and some combinations of these on polylactosamine chains; O-glycan core structures such as T-antigen Galβ3GalNAcαSer/Thr-Protein, Tn-antigen GalNAcαSer/Thr-Protein or sialyl Tn-antigen NeuNAcα6GalNAcαSer/Thr-Protein. Presence of non-human structures such as N-glycolyl-neuraminic acid in cancers has also been indicated. Association and specificity of oligosaccharide structures with regard to cancers have been well established only in few cases, some of the structures are present in normal cells and tissues and are possibly only more concentrated in cancers. However, absolute cancer specificity is probably not always needed for therapeutic applications.
LacdiNAc (GalNAcβ4GlcNAc)-type glycosylations have not been found to be commonly present on human tissues. However, LacdiNAc-type saccharide sequences have been reported from many non-human animals, bovine glycoproteins, human glycoprotein hormones (Manzella et al., 1997) and human glycodelin protein, reviewed in van den Eijnden et al. (1997). Generally the structure seem to be associated with invertebrate animals and early development. Several LacdiNAc variants has been reported from proteins expressed in human embryonal kidney 293 cells (Do et al., 1997). Recently the inventors described LacdiNAc-based structures from transfected fibroblast cells (Saarinen et al., 1999). This study did not show if the glycosylation is related to cancer or to the transfection of the adenoviral EIA-promoter sequence to the cells as EIA-promoter may regulate the gene expression of glycosyltransferases and thereby modify the glycosylation. LacdiNAc type saccharides were also detected among other structures from tissue type plasminogen activator of Bowes melanoma cells, but these were considered to be “nervous system associated” structures (Jaques et al., 1996) The previous studies also describe the detection of similar oligosaccharide structures from cell lines derived from solid tumors (Do et al., 1997; Jaques et al., 1996; Saarinen et al., 1999). However, carbohydrate and other cell surface antigens usually change when contacts between cells are changed, for instance, when a solid tumor is divided to single cells. Besides, cells of cell lines are possibly genetically modified and only then cultured as single cells. Cell surface glycosylations are also very specific for the differentiation status of a cell line or tissue and they are specific for a cell or tissue type. Therefore prior art discussed herein do not describe the natural glycosylation status of a single cancer cell or solid tumor tissue. However, the potential correlations of the glycosylations with cell type or differentiation status allow the use of the cancer antigen(s) for the typing of cancer cells and tumors.
The following patents describe cancer antigens and their use for making antibodies for therapeutic and diagnostic uses and for cancer vaccines. The antigen structures are not related to saccharides of the present invention:    Cancer vaccines: U.S. Pat. No. 5,102,663 describes composition comprising 9-OAc NeuNAcα8NeuNAcα3Lac-Cer (GD3) for the stimulation or the enhancement of the production of antibodies against 9-OAc GD3.    U.S. Pat. No. 5,660,834 describes pharmaceutical composition containing mucin type glycoprotein consisting essentially of Tn (GalNAcα-Ser/Thr) or sialyl-Tn antigens (NeuNAcα6GalNAcα-Ser/Thr) and uses thereof with adjuvant to reduce cancer cell growth rate. Inventions related to the same mucin sequences are also described in other patents: U.S. Pat. No. 5,747,048 (adjuvant therapy for human) and U.S. Pat. No. 5,229,289.    U.S. Pat. No. 6,083,929 describes extended type 1 chain sphingolipids (Galβ3GlcNAc) as tumour-associated compositions and pharmaceutical composition with an adjuvant.
Therapeutic antibodies: U.S. Pat. No. 4,851,511 describes a monoclonal antibody that bind disialosyl Lewis a-structure NeuNAcα3Galβ3(Fucα4)[NeuNAcα6]GlcNAc, diagnostic test kits, hybridomas producings antibodies, marker molecules and an antitumor drug conjugated with antibodies.
U.S. Pat. No. 4,904,596 describes a monoclonal antibody that binds structure NeuNAcα3Galβ4(Fucα3)GlcNAcβ3Galβ4(Fucα3)GlcNAcβ3LacCer, hybridomas, diagnostics, and coupling of the antibody to an antitumor drug, an immunoregulatory agent or a differentiation inducing agent.
U.S. Pat. No. 5,874,060 describes humanized antibodies recognizing Lewis y-antigen Fucα2Galβ4(Fucα3)GlcNAc.
U.S. Pat. No. 6,025,481 describes nucleic acid molecules encoding humanized antibodies recognizing Lewis b-antigen. The Lewis b-structure Fucα2Galβ3(Fucα4)GlcNAc-expression is increased in cancer cells. U.S. Pat. No. 5,795,961 describes also anti-Lewis b antibodies.
Diagnostics: U.S. Pat. No. 4,725,557 describes protein linked antigens Fucα3Gal-, Fucα4Gal- and Fucα6Gal-, and antibodies recognizing these structures, method of determining the cancer associated carbohydrate linkages and diagnostic kits. The antibodies bind cancer cells of human digestive system.
U.S. Pat. No. 5,059,520 describes several monoclonal antibodies recognizing blood group A-antigen GalNAcα3(Fucα2)Galβ-, which may be used for cancer diagnostics.
U.S. Pat. No. 5,171,667 describes antibodies against fucosylated type 2 lactosamines (-Galβ4(Fucα3)GlcNAcβ-) and use thereof for cancer diagnostics.
U.S. Pat. No. 5,173,292 describes monoclonal antibodies binding to Gal-globoside, Galβ3GalNAcβ3Galα4LacCer, which is a cancer specific structure.
U.S. Pat. Nos. 6,090,789 and 5,708,163 describe synthesis of Fucα2Galβ3GalNAcβ3Galα4LacCer (Globo H, MBr1, breast tumor associated antigen) conjugates and analogs thereof, and pharmaceutical compositions containing the same. U.S. Pat. No. 5,679,769 describes the synthesis of asparagines linked to glycopeptides. U.S. Pat. No. 5,543,505 describes synthetic compounds which bind Helicobacter pylori bacteria.
U.S. Pat. Nos. 5,902,725 and 6,203,999 describe the detection of prostate specific cancer by assaying at least triantennary oligosaccharides on prostate specific antigen. Antibody or lectin PHA-L is used for detection. The patents characterize chromatographically the presence of triantennary N-glycans on cancer form of PSA from a cell line.
The prior art describes fucosylated lacdiNAcs containing relatively large N-glycan structures (EP0565241) and a core 2-type O-glycan structures (EP0919563) in pharmaceutical compositions. The compositions are aimed for inhibition of selectin mediated cell adhesion and in EP0919563 also for inhibition of metastasis by inhibiting selectin mediated cell adhesion. However, the present invention is directed to the use of the oligosaccharide epitopes according to the present invention as targets of specific recognition molecules, including antibodies. The present invention is specifically directed to suitable antigenic conjugates and compositions for inducing antibodies for diagnostics and therapies. The present invention is directed to pharmaceutical compositions comprising optimal size of oligosaccharide sequences for recognition by specific antibodies. The optimal oligosaccharide epitopes may comprise only the terminal lacdinac structure or the terminal oligosaccharide sequence and one or two monosaccharide residues.